Phosphine oxide flame retarded, rubber-modified, polyphenylene ether resin compositions

Abstract

Polyphenylene ether resin compositions are flame retarded by using specified phosphine oxides of the formula (R).sub.3 P═O wherein R is alkyl, haloalkyl, phenyl, halophenyl, benzyl, alkylbenzyl, or cycloalkyl.

What is claimed is: 
     
       1. A flame retardant composition comprising a homogenous blend of polymers containing about 10 to 90 parts by weight of polyphenylene ether resin, about 90 to 10 parts by weight of polystyrene, and a flame retardingly effective amount less than 6% by weight based upon the blend of polymers of a compound of the formula   (R).sub.3 P═O     wherein R is (alkyl containing about 1 to 6 carbon atoms) n-propyl or n-butyl.   
     
     
       2. The composition of claim 1 wherein the blend contains about 50 to 80 parts by weight polyphenylene ether resin and about 20 to 50 parts by weight of polystyrene. 
     
     
       3. The composition of claim 1 wherein the blend is about 50 parts polyphenylene ether and about 50 parts polystyrene. 
     
     
       4. The composition of claim 1 wherein the phosphine oxide is incorporated in an amount of about 4% by weight based upon the blend of polymers. 
     
     
       5. The composition of claim 4 wherein R is n-propyl. 
     
     
       6. The composition of claim 1 wherein R is n-butyl.